check dims before using

matlab/gdat.m

@@ -188,7 +188,7 @@ try
     args = [{shot,data_request},varargin_eff];
   end
   % treat multiple shot numbers
-  if exist('shot') && isnumeric(args{1})
+  if exist('shot') && numel(args) > 0 && isnumeric(args{1})
     args_in = args;
     for i=1:numel(shot)
       args{1} = shot(i);
@@ -215,11 +215,13 @@ catch ME_gdat
   return
 end
 
-for i=1:numel(gdat_data)
-  gdat_data(i).gdat_call = gdat_call;
+if numel(gdat_data) > 0
+  for i=1:numel(gdat_data)
+    gdat_data(i).gdat_call = gdat_call;
+  end
 end
 
-if gdat_data(1).gdat_params.doplot
+if numel(gdat_data) > 0 && gdat_data(1).gdat_params.doplot
   try
     % plot gdat_data versus 1st dim by default, if nb_dims<=2, otherwise do not plot
     hhh = gdat_plot(gdat_data); % return handle to figure